Synthetic detergent compositions

ABSTRACT

A synthetic detergent composition having particular utility in the making of synthetic detergent bars comprising a major proportion of primary alkane sulfonates derived predominantly from alpha-olefins containing from 11 to 20 carbon atoms, especially 18 to 20 carbon atoms, and minor amounts, each, of the following: (a) at least one water-soluble inorganic salt, (b) a plasticizing and/or binding agent such as a higher molecular weight alcohol, a higher molecular weight fatty acid, or a polyhydric alcohol, or mixtures thereof, and (c) a mineral oil which is substantially free of alkanes containing less than 17 carbon atoms. The mineral oil component most advantageously is obtained from the unreacted alkanes carried over from the sulfitation of the alpha-olefins.

United States Patent [54] SYNTHETIC DETERGENT COMPOSITIONS 6 Claims, No Drawings [52] U.S. C1 252/554 [51] Int. Cl Clld 1/12 [50] Field ol'Search 252/138,

[56] References Cited UNITED STATES PATENTS 2,385,614 5/1941 Dreger et al. 252/161 2,868,731 1/1959 Henderson et a1 252/1 17 2,894,912 7/1959 Geitz 252/121 3,001,948 9/1961 Clippinger 252/152 3,186,948 5/1965 Sweeney 252/161 3,224,976 12/1965 Farrar et a1 252/119 FOREIGN PATENTS 232,429 2/1961 Australia 252/121 636,022 2/1962 Canada 252/121 858,075 l/l96l Great Britain. 252/16! 905,952 9/1962 Great Britain... 252/121 950,233 2/1964 Great Britain 252/161 Primary Examiner-Leon D. Rosdol Assistant ExaminerP. E. Willis Attorneys-Joseph C. Herring, Richard C. Willson, lr., Jack L. Hummel and Wallenstein, Spangenberg, Hattis & Strampel ABSTRACT: A synthetic detergent composition having particular utility in the making of synthetic detergent bars comprising a major proportion of primary alkane sulfonates derived predominantly from alpha-olefins containing from 1 l carried over from the sulfltation of the alpha-oleflns.

SYNTHETIC DETERGENT COMPOSITIONS A vast amount of work has been directed toward the development of a synthetic detergent bar which can compete successfully with conventional household toilet soap bars. While, as a result of such work, various problems involved in the making of synthetic detergent bars have been solved, they still have a number of disadvantages which have impeded their widespread acceptance as a replacement for conventional bar soaps. Significant among these disadvantages is the tendency of synthetic detergent bars, & heretofore made, to deoil the skin excessively with the result that the skin becomes irritated. In an effort to circumvent this problem, various oils, such as lanolin, have been compounded into synthetic detergent bars. This practice, however, while adding to the cost of manufacturing the bars, has not provided a satisfactory solution to the problem.

In accordance with the present invention, synthetic detergent compositions having special utility in bar form are provided which effectively overcome the irritation to human skin, resulting from the deoiling thereof by synthetic detergent bars as heretofore manufactured, without the necessity for adding emollients such as lanolin to the compositions. This unique ability of synthetic detergent bars made from the compositions of this invention, moreover, is complemented by other desirable properties, namely, proper rate solubility, good detersive and lathering characteristics, freedom from stickiness, high resistance to water hardness, smooth surface feel commonly referred to in the art as good slip or finish," low hygroscopicity, a pleasant odor even without the addition of perfumes, and the ability to be produced in conventional soapmaking equipment.

The objectives of the present invention, in brief, are attained with synthetic detergent compositions which incorporate, as essential ingredients, (a) alkane sulfonates derived predominantly from alpha-olefins containing from 11 to 20 carbon atoms, (b) at least one water-soluble inorganic alkali metal salt, (c) one or more binding and/or plasticizing agents, and (d) a mineral oil which is substantially free of alkanes containing less than 17 carbon atoms. The generally optimum objectives of the invention are attained with compositions wherein the alkane sulfonates are derived from alpha-olefins which are essentially linear in structure and contain from to 20, especially desirably 18 to 20, carbon atoms, and wherein the mineral oil component comprises unreacted alkanes carried along from the alpha-olefin sulfitation reaction. The utilization of alpha-olefins of higher molecular weight and a narrower carbon number range favors the production of a bar having reduced solubility and, therefore, a longer useful life. The utilization of the unreacted alkane fraction from the alpha-olefin sulfitation reaction as the mineral oil component, in accordance with the especially preferred practice of this invention, elficiently, effectively and economically provides a mineral oil which is similar in composition to mild baby oils derived from U.S.P. mineral oil and which, moreover, is substantially free of hexadecane known to contribute to hyperkeratosis.

The alpha-olefms utilized in preparing the alkane sulfonates contemplated by the present invention can be derived from any convenient source. One such source is the alpha-olefins obtained from the cracking of petroleum wax. Commercial sources, comprising about 90 percent, or more, for instance, 95 percent to 98 percent, of l-alkenes can also be employed. As indicated, the alkane sulfonates having utility for the purposes of this invention are those derived from alpha-olefins of the specified carbon content, and are essentially of normal or straight-chain structure. it should be understood, or course, that a small amount, of the order of l percent to 6 percent, of branched chain materials may be present without impairment to the properties of the synthetic detergent bars produced with the compositions of this invention. Accordingly, characterization herein of the alkane sulfonates as primary, normal or straight-chain" is to be understood to mean that the sulfonates are derived predominantly from alpha-olefins which are mainly of linear character, but which may contain a small percentage of branched chain materials.

The use of alpha-olefins in the formation of sulfitation detergent materials having utility in making synthetic detergent bar products is disclosed, for example, in US. Pat. Nos. 3,001,948 and 3,231,606. The sulfitating agents used in ma!- ing the detergent bar products of those patents are of the type which can be employed in the practice of the present invention. Thus, the sulfitating agent used to form the primary alkane sulfonates contemplated by this invention may be an alkali metal bisulfite such as potassium or sodium bisulfite. Exemplary of other sulfitating agents which can be used are ammonium bisulfite, and aliphatic amine or pyridine bisulfites. In addition, compounds which, in solution, are converted to bisulfites can be utilized as, for example, sodium or potassium metabisulfite. The reaction between the alpha-olefins and the sulfitating agent can be carried in any convenient manner known in the art. Of the aforementioned sulfitating agents, potassium compounds are preferred since alkane sulfonates produced therewith provide synthetic detergent bars having improved solubility characteristics.

The water-soluble inorganic metal salt component of the synthetic detergent compositions of this invention advantageously is an alkali metal sulfate or bisulfite, specific examples of which are sodium sulfate, sodium bisulfite, sodium acid sulfate, potassium sulfate and potassium bisulfite. Mixtures of such salts, of course, can be employed. In the formation of the alkane sulfonates used in the compositions, some inorganic metal sulfate is produced as a byproduct of the sulfitation reaction. This in situ formed sulfate, to the extent that it does not exceed the amount of this component required to produce a synthetic detergent bar having the properties specified, may be carried over with the alkane sulfonates from the sulfitation reaction. The water-insoluble inorganic metal salt component, while being essentially inert, contributes to the overall soaplike character of the bars and aids in the formation thereof.

The plasticizing and/or binding agents utilized in the compositions of the invention may be selected from a wide variety of materials. Most advantageously, however, this component comprised a member of the group consisting of higher molecular weight alcohols, higher molecular weight fatty or monocarboxylic acids, and polyhydric alcohols, and compatible mixtures thereof. Exemplary of higher molecular weight alcohols useful in preparing the compositions are hexadecanol, lauryl alcohol, stearyl alcohol, nonadecyl alcohol, and the like, and mixtures thereof. Of this group, hexadecanol is preferred. The higher molecular weight fatty acids utilized especially desirably are solid at ordinary or room temperatures. Examples of such acids are myristic acid, palmitic acid, stearic acid, arachidic acid, melissic acid, and the like. Generally speaking, it is preferred to use those of such acids which have in the range of 18 to 22 carbon atoms, stearic acid, or commercial sources of stearic acid such as triple-pressed stearic acid, being especially satisfactory. The polyhydric alcohols useful in formulating the composition of this invention include glycerols such as glycerin, amylglycerol, diethylglycerol, and the like; and glycols exemplified by propaneglycol, polyethylene glycols, polypropylene glycols; and the like. Glycerine is the particularly preferred material of this group.

The mineral oil constituent of the compositions, as indicated, particularly advantageously comprises the unreacted alkanes carried along with the alkane sulfonates derived from the sulfitation of the alpha-olefms. These alkanes, as stated, are essentially free of hexadecane, and generally speaking, provide, directly in the reaction mixture, an amount of mineral oil in the compositions capable, when the compositions are formed into bars, of imparting an oleostasis property to the bars that substantially improves the after-use feel" thereof, and, for all practical purposes, coacts to overcome the irritation problems due to deoiling of the skin caused by synthetic detergent bars as heretofore made. While the quantity of mineral oil derived from this source is, most instances, sufficient, commercial grade mineral oils, as well as other sources thereof, which oils satisfy the criteria specified, also may be incorporated into the compositions, if desired, to enhance, augment or improve the effects attained with the mineral oils carried along with the sulfitation reaction products.

The proportions of the various components comprising the essential ingredients of the compositions of this invention are somewhat variable. The primary alkane sulfonates constitute by far the greatest proportion of the compositions, ranging, by weight,- from about 50 percent to 90 percent, especially desirably from about 60 percent to 85 percent, thereof, with the generally optimum objectives of the invention being attained with compositions comprising, basis weight, from about 65 percent to 75 percent of the alkane sulfonates. The amount of water-soluble inorganic alkali metal salt incorporated in the compositions ranges from about 2 to 3 percent to about 12 percent, usually about 5 percent to about percent, by weight of the compositions. The amount of plasticizing and/or binding agent used should range from about 3 percent to about l5 percent, with a range of about 5 percent to about 10 percent, by weight, being preferred. The residual mineral oil content of the compositions, generally speaking, should range from about 1 percent to about 10 percent, especially desirably from about 2 percent to 5 percent, by weight, of the compositions. The water content of the compositions ranges from about 2 percent to about 12 percent, usually about 3 percent to 8 percent, by weight based on the alkane sulfonates. Small amounts, of-the order of about 1 percent to about 5 percent, by weight, of materials such as perfumes, pigments, fillers and the like, also may be incorporated into the compositions without unduly adversely affecting the properties of synthetic detergent bars formed from the compositions. As stated earlier hereinabove, the compositions have an inherent, or building, pleasant odor. Thus, only very small amounts of perfume need be used to provide, from the standpoint of odor, a commercially acceptable synthetic detergent bar. The wear rate of bars produced in accordance with the practice of this invention ranges from about 0.7 to about 1.5 g. per hand wash. The hardness of the bars ranges from about 5 to about 18.

In order that those skilled in the art may even more fully understand the nature and advantages of the present invention, an illustrative example of carrying out the invention will be described. it should be understood, of course, that the same is not to be construed in any way as Iimitative of the full scope of the invention.

EXAMPLE a. A mixture is formed of alpha-olefins, derived from the cracking of petroleum wax and containing predominantly 18 to 20 carbon atoms, in an aqueous alcohol solvent, and potassium bisulfite. The sulfitation reaction is allowed to proceed at 40 C. for 5 hours. The reaction mixture is agitated throughout. Thereafter, the pH of the reaction mixture is adjusted to 8 with dilute potassium hydroxide and the mixture is evaporated to dryness. The product is a white, friable solid. It analyzes as follows: primary alkane sulfonate 82 percent; residual mineral oil 9.5 percent; water 7.5 percent. The mineral oil is substantially free of hexadecane.

b. To 15 g. of the white solid of part (a) hereof, L5 3. of hexadecanol and 1.5 g. of sodium sulfate are added. The mixture is thoroughly agitated and is then formed into a bar. The bar is white, firm and forms a good lather. When it is used to wash hands, it does not irritate the skin and provides an afteruse feel similar to that of conventional soap bars.

What is claimed is:

l. A synthetic detergent composition for use in bar form consisting essentially of, basis weight, (a) from about 50 to 90 percent of alkane sulfonates derived predominantly from alpha olefins containing from 18 to 20 carbon atoms, (b) from about 2 to 12 percent of at least one watersoluble inorganic alkali metal salt of the group consisting of alkali metal sulfates and bisulfites and mixtures thereof, (c) from about 3 to 15 percent of at least one binding agent selected from the group consisting of higher molecular weight monohydric alcohols,

normally solid higher molecular weight fatty acids, and polyhydric alcohols of the group consisting of glycerols and glycols and mixtures thereof, and mixtures of said agents, and (d) from about 1 to about 10 percent of a mineral oil consisting essentially of unreacted alkanes carried along with the alkane sulfonates derived from said alphaolefins, said mineral oil being substantially free of alkanes containing less than 17 carbon atoms.

2. A synthetic detergent composition according to claim 1 wherein the binding agent is hexadecanol.

3. A synthetic detergent composition according to claim 1 wherein the alkane sulfonates are essentially potassium normal alkane sulfonates.

4. A synthetic detergent composition according to claim 1 wherein the mineral oil comprises from about 2 to about 5 percent, by weight, of the composition.

5. A synthetic detergent bar consisting essentially of, basic weight, (a) from about 60 to 85 percent of alkane sulfonates derived predominantly from linear alpha-olefins containing l8 to 20 carbon atoms, (b) from about 5 to about 10 percent of a water-soluble inorganic alkali metal salt of the group consisting of alkali metal sulfates and bisulfites and mixtures thereof, (c) from about 5 to about 10 percent of at least one binding agent selected from the group consisting of higher molecular weight monohydric alcohols, normally solid higher molecular weight fatty acids, and polyhydric alcohols of the group consisting of glycerols and glycols and mixtures thereof, and mixtures of said agents, and (d) from about 1 to about 5 percent of a mineral oil substantially free of hexadecane, said mineral oil comprising unreacted alkanes carried along with the alkane sulfonates derived from said alpha-olefins.

6. A synthetic detergent bar according to claim 8 wherein the (0) component is hexadecanol.

3,622,517 NOV. 23, 1971 Patent Iu'o.

Dated Charles J. Norton Inventon's) If is CEflTtiIlBd that r-xm'r appears in the ahove--identified patent: and LlzaL said LetLers PdLcnL are hereby corrected as shown he ow:

Col. 1, line 25: "rate solubility" should read rate of solubility-- Col. 3, line 33: "building" should read -built-in Col. 4, line 52: "8" should read --5 Signed and sealed this 6th day of June 1972.

(SEAL) Attest:

EDWARD M.FLETCHER, JR. ROBERT GOTTSCHALK Attes ting Officer Commis sioner of Patents 

2. A synthetic detergent composition according to claim 1 wherein the binding agent is hexadecanol.
 3. A synthetic detergent composition according to claim 1 wherein the alkane sulfonates are essentially potassium normal alkane sulfonates.
 4. A synthetic detergent composition according to claim 1 wherein the mineral oil comprises from about 2 to about 5 percent, by weight, of the composition.
 5. A synthetic detergent bar consisting essentially of, basic weight, (a) from about 60 to 85 percent of alkane sulfonates derived predominantly from linear alpha-olefins containing 18 to 20 carbon atoms, (b) from about 5 tO about 10 percent of a water-soluble inorganic alkali metal salt of the group consisting of alkali metal sulfates and bisulfites and mixtures thereof, (c) from about 5 to about 10 percent of at least one binding agent selected from the group consisting of higher molecular weight monohydric alcohols, normally solid higher molecular weight fatty acids, and polyhydric alcohols of the group consisting of glycerols and glycols and mixtures thereof, and mixtures of said agents, and (d) from about 1 to about 5 percent of a mineral oil substantially free of hexadecane, said mineral oil comprising unreacted alkanes carried along with the alkane sulfonates derived from said alpha-olefins.
 6. A synthetic detergent bar according to claim 8 wherein the (c) component is hexadecanol. 